Allergy to pets can
be a very difficult problem, especially cats. This is because the
particles of dried saliva from licking themselves and their skin
scales are so light that they remain floating in the air for a very
long time. Cats are now so common that schools, public buildings,
cinemas, buses and trains, and the clothes and even the hair of cat
owners, all contain enough cat allergen to set off a very sensitive
asthmatic. So even if you do not own a cat or have taken advice to
find it a good home there is still some cat allergen floating in the
air in most places.

An example is the patient who was very allergic to cats who was
considering buying a house. He finally purchased after being assured
by the previous owners that although they had a dog they had never
had a cat. On taking up residence he was repeatedly admitted to
hospital with asthma. Skin test for dog was negative but cat was
very positive. All became clear when he found out that the cat next
door used to come in every night and curl up in front of the fire
with their dog, but of course strictly speaking the cat did not
actually live there!! He had to re-decorate that house from top to
bottom before the effects of the cat were eliminated. Recent
research has found that some infants who are raised with cats may
become immune to them, while others become very allergic, so there
is some controversy regarding the best policy.

Another patient found that every time he spent the evening in his
local pub he had a very bad night with asthma, so he was advised to
stop drinking beer as the being the most likely cause. He had no
problem while drinking vodka for some months in different pubs, but
when he went back to his local some time later he found that beer
had no effect. What he had not told me was that in the meantime the
owners of the pub had gone bankrupt, and the new owners cleared out
the cats which had infested the place, and sat on the window sill
watching him drinking his beer!

For some years patients waiting to see me sat on a sofa covered with
a very old tiger skin. One day I noticed that a little boy who was
cat allergic, and had been much better since their cats had been
found a good home, was sniffling and wheezing by the time he came in
to see me.

Recalling that tigers are just the big cats, I made an
extract of some Tiger hair for testing with the result shown.

From the allergy point of view there does not seem to be much
difference between various breeds of cat, so I made a testing
extract from the hair of a Siamese cat and compared the skin test
reactions on the owner of the cat, which seems to confirm that there
is not much difference between breeds of cat. Test extracts I made
from long and a short haired cats showed that the long haired cat
was much more allergenic than the short haired, as I expected.

Dogs are not such a problem to the allergic person, as they do not
seem to contaminate the environment so much. Allergy to the Mexican
hairless dog has been reported, but I have never seen this. One
unique patient is definitely very allergic to dogs, but not to the
bitches which she has kept for many years in very close contact.

Dogs can also cause other allergic problems, such as eczema. Because
the possibility is very seldom considered dogs are unlikely to be
diagnosed as the cause of eczema, so the true frequency of dog
eczema is completely unknown. The clue is often that a holiday in
the sun, which helps most cases of eczema anyway, brings notable
improvement in the child’s eczema, and the longer the holiday the
better. On return home the eczema flares up overnight, because of
environmental allergens.

The boy with eczema illustrated above had improved on a milk free
diet, and then cleared completely on holiday in Spain. On the way
home from the airport in the car for one hour with the dog which had
just been collected from kennels, this boy began to scratch himself
to pieces, and three days later he was as shown. After removal of
the dog and a house-cleaning, and continuing the milk free diet, his
eczema completely cleared. The lesson is that there are often
several causes of eczema, and that the possible effects of
environmental allergens should never be overlooked.

In my experience to find the dog a new home or put it outside in a
kennel is more effective than finding a home for a cat. Ignorance of
the possible effects of a resident dog can give rise to gross
injustice. For example, Sandra was aged 12 when she was finally seen
at the clinic with a referral letter stating that she had chronic
asthma with a major emotional factor because her father was
frequently in trouble with the law and often in jail.

She just sat there very withdrawn, hunched up, and completely
inactive, her appearance suggesting that there was indeed an
emotional problem. Her best peak flow was only 50 litres/min, a very
low figure indeed, so she did not have enough breath to do more than
sit still !! The peak flow record above shows how wrong that
diagnosis was, because after rescue with a course of oral steroids
she was not properly controlled with Becotide until the dog was put
outside in a kennel. Some months later she stopped all medication
and remained free from asthma.

When a pet is proved or suspected to be the cause of asthma in a
child the parents often have difficulty in accepting that their
beloved pet is the cause, and that removal is the only sensible
answer as desensitisation is not possible in this country. We are
such a nation of dog lovers that these priorities may not be
acceptable, so that expensive drugs are often being prescribed to
suppress the effect of the continued presence of the animal. This
policy may not be pursued vigorously because many doctors are fond
of dogs and have dogs themselves, or they are unaware or do not
accept the importance of allergy to pets.A recent survey showed
that in this country advice to find a pet a good home is not usually
pursued vigorously.

The most important evidence indicating the pet is the cause of the
problem, whether it be rhinitis, asthma, or eczema, is recovery on
holiday followed by swift relapse on return home. This scenario is
also typical of dust mite allergy, so skin tests and monitoring the
effects of being away from home in a dog free environment on the
peak flow may be necessary to confirm that the dog is the culprit.

This is an example of a case where the boy’s mother could not accept
that her beloved pet could be the cause of her son’s asthma, which
was so severe and chronic that he had a severe pigeon chest
deformity as a result.

The peak flow chart illustrates how he recovered with high dosage
steroids in hospital, relapsed promptly
on return to his dog
contaminated home, and stabilised on the removal; of the dog and its
traces.

Horses are another cause of allergy, particularly asthma, which can
also have emotional aspects. When I discovered that a little boy’s
life-threatening asthma attacks were caused by his elder sister
carrying horse dander into the house on her riding clothes she was
so incensed that she wished him dead!

The use of horse hair as stuffing in antique furniture is also an
unusual cause., as in the teenager who began sneezing and wheezing
when he lay on his stomach on an antique sofa looking at TV, and had
asthma every night because he was sleeping on a mattress which was
40 years old and full of mites. Renewal of the mattress and
avoidance of the sofa were remarkably effective.

Grooming horses produces a surprising amount of horse dander which
triggers off the asthma or rhinitis. Horses eat hay, and if the
owners are pollen sensitive they may get hay fever when handling hay
which was pollinating when it was harvested, but can tolerate
‘seeds’ hay which has already pollinated.

The environment of the stable harbours other potential causes of
trouble for the allergic horse owner, because if hay is mouldy it
can also cause not only serious asthma and allergy, but also
farmer’s lung, which can be really serious for both rider and horse.
They should always be asked if exposure to mouldy hay is followed by
influenza-like symptoms suggestive of farmers lung.. The bedding of
the horse is also a potential source of trouble, but this can be
dealt with by substituting synthetic material which is now
available. Horses can get allergies too!

A chronic asthmatic patient had a horse which was shown by a RAST
test to be very allergic to three species of mite, grass pollen, and
all cereals. This finding created great problems!.

Any pet can cause a problem, and a special testing solution may not
be available. A good example is the lady who developed rhinitis with
very severe sneezing attacks. Her little boy had been given a
chinchilla for his birthday some time before she developed her
problem, and she got better on holiday. The chinchilla is a rodent
from South America which can be used to make very expensive fur
coats.

Because skin tests for dust mite and all common allergens were
negative she was asked to come back with a sample of the animal’s
hair, and also some house dust collected from the top of the
wardrobe. She brought only a few wisps of hair, but this was enough
to make an extract in a syringe which produced an immediate skin
reaction, and so did an extract of the dust from the top of the
wardrobe., as shown, but the usual dust mite test was negative.
Fortunately she was soon to move house, so it was advised that the
chinchilla be kept outside after they moved to the new house, and
there was no further trouble with allergic rhinitis.

Any exotic pet can cause allergy problems in allergic people, the
strangest in my experience being a Kinkajou. For many years nobody
suspected, especially the skin clinic, that this was the cause of
this teenager’s chronic eczema. He had generalised eczema as well,
worst on the hands which touched the animal. When the animal died
the eczema cleared up completely!.

Yvonne was 37, worked at the hospital and had been plagued with
eczema for 14 years which mainly affected her face. She was using
antihistamine to suppress itching in bed, and steroid creams. She
had become anxious about long-term effects on her skin, but the
dermatology department had no further suggestions.. She had had a
dog for 18 years, and the eczema improved when on holiday in Europe.
Skin test for dog was +++, and RAST was ++++, but she was very
anxious not to have to get rid of the dog as she was so fond of it.

At the time some research was being carried out with tannic acid,
which has the property of binding and coagulating proteins such as
dog dander. She was supplied with tannic acid to make up and use as
a spray everywhere in the house, and the eczema disappeared
completely for over two months. At that point she found that on
return from holiday the effect of the dog became evident again, but
with further use of the tannic acid the eczema again subsided.
Tannic acid was fairly easy to obtain, but strong tea is a good
substitute.

"It
is a paradox that while Britain has the highest incidence of
allergic disease in the world, it also has the most inadequate
allergy service"